Monoazo dyestuffs



Patented Apr. 25, 1939 UNITED STATES PATENT OFFICE 2,155,493 MONOAZODYESTUFFS No Drawing. Application November 12, 1936, Se-

rial No. 110,458. In Great Britain November 7 Claims.

The present invention relates to the manufacture of new monoazodyestuffs which are useful for the colouring of Wool.

It is known to make azo dyestuffs by coupling the diazo compounds of thebutyl esters of aminobenzoic acids with sulphonated components, seeBritish Specification 314,768.

An object of the present invention is to make new monoazo dyestuffswhich will dye wool to give dyeings of improved fastness to washing andmilling.

This object is attained by coupling a diazotised aminocarboxylic esterof the general formula where Ar is a divalent radicle of the benzeneseries and R is a long chain aliphatic radicle of at least 10 carbonatoms, and not more than 20, with a coupling component devoid of longchain aliphatic hydrocarbon residues and having at least one sulphonicor carboxylic group.

The first components used according to the present invention are, aswill be seen, esters of aliphatic alcohols of 10-20 carbon atoms. Thesealcohols, which are used as starting materials in the making of theintermediates to be used according to the invention, comprise dodecylalcohol, otherwise known as dodecenol, tetradecyl alcohol, hexadecylalcohol, octadecyl alcohol, all of which are saturated. Hexadecylalcohol is the main or sole component of the alcohols obtained by thesaponification of spermaceti. If the alcohol obtained by thesaponification of spermaceti is regarded as hexadecyl alcohol, itspurity will depend upon the purity of the spermaceti which has beensaponified. With low grade spermaceti the alcohol obtained is a mixturewhich may contain also oleyl alcohol. When the term cetyl is used inthis specification, it will be understood that it does not necessarilyrefer to pure cetyl alcohol.

The invention is not limited to the use of esters of the alcoholsmentioned above, although in practice it will be found that it is atpresent limited to the use of alcohols containing an even number ofcarbon atoms. Dodecyl and tetradecyl alcohols are obtainable byreduction of the fatty acids obtained from coconut oil and palm oil.Other alcohols, e. g. olein or oleyl alcohol (better to be known asoctadecenol) are likewise obtainable by reduction of the fatty acids ofnatural fats and oils (see here, for instance, Bouvaltt and Blane, Bull.Soc. Chim., series 3, vol. 31, page 1, pages 674 and 12 10). Theinvention contemplates the use of the said esters of any of thesealcohols, whether in the pure state or as obtained as mixtures from thefatty acids of natural fats and oils. Convenient alternative descriptionof the said esters is accordingly that they are those of primaryalcohols resulting from the reduction of the fatty acid radicles ofnatural fats and oils or from the saponification of waxes.

The new dyestufis of the present invention are soluble in water and dyewool to give dyeings which are characterised by their superior fastnessto washing and milling compared to the known dyestuffs of BritishSpecification 314,768.

As coupling components we may use, for example, naphthol sulphonicacids, aminonaphthol sulphonic acids or their N-substituted derivatives,naphthylamine sulphonic acids, sulpho-arylpyrazalones and the like.

The invention is illustrated but not limited by the following examples,in which the parts are by weight.

Ewample 1 30.5 parts of dodecyl-p-aminobenzoate (melting point 77-78 C.)are diazotised as a suspension in 250 parts of water and 26 parts of 36%hydrochloric acid by the addition of '7 parts of sodium nitrite. Thediazo suspension so obtained is then added to an aqueous solution of30.5 parts of 2-naphthol-6:8-disulphonic acid kept alkaline to litmusduring the addition by means of sodium carbonate. The dyestuff, which issalted out if necessary, is filtered off and preserved as paste or driedin any suitable way. When dry it forms a reddish orange powder whichdissolves in water or in concentrated sulphuric acid to give orangesolutions. It dyes wool in bright orange shades of excellent fastness towashing and milling and very good fastness to light.

If instead of dodecyl-p-aminobenzoate there is useddodecyl-m-aminobenzoate, rather yellower shades of orange are obtainedon wool and having similar fastness properties to Washing, milling andlight.

Example 2 The .diazo suspension prepared as in Example 1 from 30.5 partsof dodecyl-p-aminobenzoate is added to an aqueous solution of 36.1 partsof acetyl-H-acid (1-acetamino-8 -naphthol 3 :6 disulphonic acid) keptalkaline to litmus during the addition by means of sodium carbonate. Thedyestuii is salted out if necessary and filtered ofi and dried. It dyeswool in red shades of very good fastness to washing, milling and light.

Example 3 A suspension of 33.5 parts of dodecyl-3-amino-4-methoxy-l-benzoate (M. P. 50 C.) in 250 parts of water and 26 parts of36% hydrochloric acid is diazotised by the addition of 6.9 parts ofsodium nitrite. The solution of the diazo compound so obtained isfiltered if necessary and added to a cooled aqueous solution (5 C.) of30.5 parts of 2-naphtho1-6:S-disulphonic acid kept alkaline to litmusduring the addition by means of sodium carbonate. The dyestuff formed isat first gelatinous but after the addition of salt and stirring for20-30 hours it separates in a filterable condition and is filtered off,Washed with 10% brine and dried. The new dyestuif dyes wool in brightreddish orange shades of excellent fastness to washing and milling andvery good fastness to light.

If in the above example instead of 30.5 parts of 2-naphthol-6B-disulphonic acid there are used 36.1 parts ofl-acetamino-8-naphthol-4:G-disulphonic acid, a new dyestuff is obtainedwhich dyes'wool in bright red shades of excellent fastness' to severewashing and milling and very good light fastness.

' Example 4 30.5 parts of dodecyl-p-aminobenzoate are diazotised as inExample 1 and the resulting diazo compound is added to an ice-coldaqueous solution of 25.4 parts of l-(4'-sulphophenyl) -3-methyl-5-pyrazalone which is kept alkaline during the addition by meansof sodium carbonate. When coupling is complete the mixture is heated to50 C., salted with 20% common salt, cooled to 15-20 C. and the dyestufffiltered oil. After washing the dyestufi paste with 15% brine it isdried or preserved as a paste. When dry the new dyestuff forms ayellowish brown, slightly waxy solid which dissolves in hot water to ayellow solution and in concentrated sulphuric acid toa greenish yellowsolution. It dyes wool in yellow shades of very good fastness to severewashing, milling and light.

Example 5 A mixture of 31.9 parts of dodecyl-3-amino-4-methyl-l-benzoate (M. P. 55-55.5 C.), 500 parts of water and 26 parts of36% hydrochloric acid off, washed with 5% brine and dried. it dyes woolin bright greenish yellow shades of excellent iastness to severe washingand milling and very.

good fastness to light.

Example 6 A suspension of 33.5 parts ofdodecyl-B-aminoi-methoxy-l-benzoate in 250 parts of water and 26 partsof 36% hydrochloric acid is diazotised by the addition of 6.9 parts ofsodium nitrite. The solution of the diazo compound so-obtained isfiltered if necessary and added to an ice-cold aqueous solution (5 C.)of 25.4 parts of 1-(4'- sulphophenyl)-3-methyl-5-pyrazalone which iskept alkaline to litmus during the addition by means of sodiumcarbonate. After stirring for some hours the mixture is heated to 50 C.and the dyestuff filtered ofi, washed with a little 5% brine and. dried.The new dyestufi is a reddishyellow powder when dried which dissolves inhot Water to a reddish-yellow solution and in concentrated sulphuricacid to a reddish-yellow solution. It dyes wool in reddish-yellow shadesof very good fastness to severe washing, milling and light.

Example 7 30.5 parts of dodecyl-p-aminobenzoate are diazotised as asuspension in 250 parts of water and 26 parts of 36% hydrochloric acidby the addition of 7 parts of sodium nitrite. The diazo suspensionso-obtained is then added to a cooled aqueous solution of 32.3 parts of1-(2':5-dichloro-4'-sulphophenyl) -3-methyl-5-pyrazalone which is keptalkaline to litmus during the addition by means of sodium carbonate.When coupling is complete the coupling mixture is at first like a thinjelly but after salting with 5% common salt (weight for volume) andstirring for several hours the dyestuff separates in granular form andis filtered off and dried. The new dyestuff when dry is a yellow powder.It dissolves in hot water to a yellow solution and in concentratedsulphuric acid to a yellow solution. It dyes wool in greenishyellowshades of excellent fastness to severe washing, milling and light.

Further examples of dyestuffs made according to the present inventionare listed in the following table.

Example Diazo component Coupling component Shade on wool 3Oety1-m-aminobenzoate l-amino-8-naphthol-3zfi rlisulphonic acid Dullviolet. 9 Dodecyl-3-amino-4-methoxy-1-ben-2-N-fl-h1y(d)roxyethylamino-S-napnthol-fi-sulphonic acid (alkalineBrown.

zoate. coup e 10 do1(2:5-dichloro-4'-sulpl1opheny1)-3-methyl-5-pyrazalone Yellow. 11 dol-naphthol-3:fi-dis'ulphonic acid Scarlet. 12 ,do.l-(4-sulphophenyl)-fi-pyrazalone-Ii-carboxylic acid Yellow 13 d1-(4-sulphopl1enyl)-3-metl1yl-5-pyraza1one Do.

l-benzoylamino-8-naphthol-3zfi-disulphonic acid Very bluish red,l-acetamino-8naphthol-4:6-disulphonic acid Crimson red. do2-N-acetyl-N-B-hydroxy-ethylamino-8-naphthol-o-sulphonic acid.Red-brown. Dod'ecyl-2-chloro-5-am1no-l-benzoatel-acetamino-8-naphthol-4zfi-disulphonic acid Dull red. ol-naphthol-3:6-disu1phonic acid Orange-brown.

Decyl-p-arnino-benzoate l-acetamino-B-naphthol-M-disulphonic acid Red.Dodecyl 3 amino 4 methoxy 1'- l-naphthol-3:G-disulphonic acidReddish-orange.

benzoate. do l(4-sulphophenyl)-5-pyrazalone-ii-carboxylic acid Yellow.do l-acetamino-B-naphthol-i:fi-disulphonic acid Bright red.

is heated to 65 C. and then cooled with stirring to 5 C. The dispersionso-obtained is then diazotised by the addition of 6.9 parts of sodiumnitrite. The diazo solution so-obtained is filtered if necessary andthen added to a cooled aqueous solution of 32.3 parts ofl-(2':5'-dichloro-4'-sulphophenyl)-B-niethyl-S-pyrazalone, which 'iskept alkaline to litmus during the addition by means of sodiumcarbonate. Coupling is rapid and when complete the newdyestufiis-filtered The compounds used as first components according tothis invention can be obtained by re-. acting the appropriate nitroaroylchloride with a suitable long chain aliphatic alcohol, in an inertsolvent, such as, for example, dry toluene, to give the correspondingnitroaryl carboxylic ester, followed by reduction of the nitro groupwith, for example, iron and aqueous hydrochloric acid.

As many apparently widely difierent embodiments of-this invention maybe'made'without departing from the spirit and scope thereof, it is to beunderstood that we do not limit ourselves to the specific embodimentsthereof except as defined in the appended claims.

We claim:

1. A compound represented by the formula in which X is the radicle of acoupling component from the group consisting of naphthol monoanddi-sulfonic acids, amino-naphthol monoand disulfonic acids,acylamino-naphthol monoand disulfonic acids, alkyl-amino-naphtholmonoand di-sulfonic acids, pyrazolone sulfonic acids, pyrazolonecarboXylic acids, and the halogen derivatives of said acids; Ar is theresidue of benzene; Y is one of a group consisting of hydrogen, methyl,methoxy and chloro; and R is a long chain aliphatic hydrocarbon radicleof at least 10 and not more than 20 carbon atoms.

2. A compound represented by the formula in which X is the radicle of acoupling component from the group consisting of naphthol monoanddi-sulfonic acids, amino-naphthol monoand disulfonic acids,acylamino-naphthol monoand disulfonic acids, alkyl-amino-naphtholmonoand di-sulfonic acids, pyrazolone sulfonic acids, pyrazolonecarboxylic acids, and the halogen derivatives of said acids; Ar isconnected to the azo bridge in one of the positions meta and para to theester group and is the residue of benzene; Y is one of a groupconsisting of hydrogen, methyl, methoxy and chloro; and R is along chainaliphatic hydrocarbon radicle of at least 10 and not more than 20 carbonatoms.

3. A compound represented by the formula in which X is the radicle of acoupling component from the group consisting of naphthol monoanddi-sulfonic acids, amino-naphthol monoand disulfonic acids,acylamino-naphthol monoand disulfonic acids, alkyl-amino-naphtholmonoand di-sulfonic acids, pyrazolone sulfonic acids, pyrazolonecarboxylic acids, and the halogen derivatives of said acids; Ar is theresidue of benzene and the azo bridge is connected to the benzene ringin one of the positions meta and para to the ester group; and Y is oneof the group consisting of hydrogen, methyl, methoxy and chloro.

4. A compound represented by the formula CnHu-O O C O OH:

in which X is the radicle of a coupling component from the groupconsisting of naphthol monoand di-sulfonic acids, amino-naphthol monoanddisulfonic acids, acylamino-naphthol monoand disulfonic acids,alkyl-amino-naphthol monoand di-sulfonic acids, pyrazolone sulfonicacids, pyrazolone carboxylic acids, and the halogen derivatives of saidacids.

5. A compound represented by the formula in which X is the residue aftercoupling of 2- naphthol-628-di-sulfonic acid; Ar is the residue ofbenzene connected to the azo bridge in one of the positions meta andpara to the ester group; Y is one of a group consisting of hydrogen,methyl, methoxy and chloro; and R is a long chain aliphatic hydrocarbonradicle of at least 10 and not more than 20 carbon atoms.

6. A compound represented by the formula in which R is a long chainaliphatic hydrocarbon radicle of at least 10 and not more than 20 carbonatoms; Ar is the residue of benzene and Y is one of a group consistingof hydrogen, methyl, methoxy and chloro; with a coupling component whichis devoid of long chain aliphatic residues and is one of a groupconsisting of naphthol monoand di-sulfonic acids, amino-naphthol monoanddi-sulfonic acids, acylamino-naphthol monoand di-sulfonic acids,alkyl-amino-naphthol monoand di-sulfonic acids, pyrazolone sulfonicacids, pyrazolone carboxylic acids, and the halogen derivatives of saidacids.

ARTHUR HOWARD KNIGHT. FRANK LODGE.

